Obtain normal human bladder and prostate tissue from surgically resected organs, from autopsied cadavers, and from perfused cadavers used for organ transplantation. Maintain dispersed cells in culture from these organs under conditions which favor the growth of differentiated epithelial cells. Develop methods to maximize the time period that epithelial cells can be grown and/or maintained in vitro. Monitor cultures periodically for mycoplasma infection and examine for chromosome number and morphology. Develop techniques for maintaining tissues in organ culture for several weeks or months. Study conditions which permit the maintenance of normal function and morphology of tissue in vitro.